Despite the global financial crisis, carbon emissions from fossil fuels rose 2% last year, leaving the Earth on a worst-scenario track for global warming, according to a new report.

The report, in today's issue of the journal Nature Geoscience, comes in the run-up to December 7-18 UN talks in Copenhagen aimed at crafting a pact to combat climate change from 2013.

The report authors also voiced concern for the world's oceans and forests, saying the capacity of these fabled "sinks" to soak up dangerous greenhouse gases was fading.

And they placed the spotlight on surging emissions by China and developing countries, explaining that a huge chunk of this carbon comes from exporting goods that are consumed in rich nations.

Global emissions from fossil fuels in 2008 amounted to 8.7 billion tonnes of carbon, an increase of 2% over 2007, say the report authors, a group of 30 climate specialists, working under the banner of the Global Carbon Project (GCP).

The average annual increase in emissions since the start of the decade has been 3.6%, and the lower annual rate of increase last year can be pinned to the start of the world financial crisis, they say.

Emissions in 2009 are predicted to fall by 2.8% in response to the financial crisis, signalling a return to 2007 levels, say the researchers, but they warn against complacency.

"Although that sounds like good news, we must remember that CO2 emissions are very tightly linked with economic activity," says Australian co-author Dr Michael Raupach of CSIRO Marine and Atmospheric Research in Canberra.

"A return to rapid emissions growth is likely as the world recovers from the GFC."

"If the recovery follows current predictions, the effect of the GFC will be as if all burning of fossil fuels had been stopped for a period of just 6 weeks," adds Raupach. "The GFC has not bought us much time."

Tracking the worst scenario

The report says emissions last year were 29% higher than in 2000, reflecting a sprint in economic growth this decade, and a massive 41% greater than in 1990, the reference year for the UN's Kyoto Protocol.

Under the IPCC's "A1F1" scenario, Earth's surface will warm by around 4°C by 2100 compared with 2000 - a rise consistent with a wipe-out of species, widespread hunger, flooding, drought and homelessness.

Sinks filling up

The oceans and forests, which absorb most of the CO2 in the seas and through photosynthesis, are failing to keep up with the gigatonnes of emissions, say the researchers.

While uncertainties are large, they estimate between 1959 and 2008, the proportion of CO2 pumped into the atmosphere that remains there has risen from about 40 to 45%, thus fuelling the greenhouse effect.

"Although the natural land and ocean sinks of carbon dioxide have shown remarkable robustness, they are vulnerable to weakening as climate change alters the planet," says Raupach.

"They have been friends to humanity, but that friendship is not unbreakable."

Developing country emissions

The researchers also say developing countries now greatly outrank rich countries as the world's biggest source of carbon emissions, a switchover that occurred in 2005.

But a quarter of their growth in emissions can be accounted for by increased trade with the West.

In China alone, 50% of the growth in emissions from 2002 to 2005 came from the country's export industries.

"The developed world has exported to the developing world the emissions it would have produced had it met its growing appetite for consumer goods itself for the last two decades," comments Professor John Finnigan, a chief research scientist, also at CSIRO Marine and Atmospheric Research.

"Developing countries have produced these goods more cheaply, leading to a fall in the real price of manufactures from cars to flat screen TVs in the US, Europe and Australia, but at the cost of greater emissions than if they were made locally."

Finnigan says the findings emphasise the need for global agreements on emissions reductions, "where attribution of emissions is far more nuanced than a simple comparison of national budgets".

Deforestation emissions down; coal emissions up

The report also says the share of total emissions from deforestation and intensive farming have fallen from 20% (in 1990-2000) to 12% (in 2008).

It says the reason emissions from this sector fell from around 1.5 billion tonnes a year to 1.1 billion tonnes in 2008 was that there were fewer forest fires in Southeast Asia and lower-than-average deforestation in Amazonia.

Raupach from the CSIRO says the implication of these changes means there is only limited scope for rich nations to offset emissions by supporting avoidance of deforestation in tropical countries like Brazil and Indonesia.

But while deforestation is on the decline, emissions from oil, gas and coal have been rising.

The report says coal surpassed oil as an emissions source for the first time in recent decades. It accounted for 40% of CO2 from fossil fuels in 2008, compared with 36% for oil.

Australia still leads the world with the highest emissions per capita among developed nations, the report says.